Sunday, October 17, 2010

High Intensity Interval Training - McMaster Study

This morning I was re-reading 90-Second Fitness. I took a break to check email and stumbled upon a health/weight loss article and came across this familiar sounding tip:

30 Second Exercise Trick

"Now you can work out less - and get more fit. A recent study from McMaster University in Hamilton, Ontario, showed that about a half-hour of sprint cycling (alternating speeds by pedaling quickly for 30 seconds and then at a slow pace for four minutes) is as effective as an hour and a half of moderate pedaling. The key is the series of 30-second power bursts."

I tracked down the study -- which was conducted 6 years ago (I guess that is recent in the big scheme of things)... The key that they aren't quoting in the "30-second power bursts" health tip is that resistance level and heart rate are really crucial. It's not just pedaling fast for 30 seconds, it is fast with lots of resistance. Think intense, almost to the point of vomiting. What they found was that the "Resting muscle glycogen concentrationincreased (P <>

The two week study was conducted in 6 session 30 minute sessions with four minutes of slow to no movement and several 30 second super intense bursts, for a total of 15 minutes of super intense "bursts" over the course of 2 weeks, with 24 hours of rest between sessions.

I rarely read the actual study that gets extrapolated and condensed to a little "weight loss fact".

The next one I'd like to track down involves incline treadmills. I read that walking at a 15% incline burns 150% more calories than walking on a flat surface. That was in the November/December 2008 issue of Fitness Magazine. I looked and no source was listed.

1 comment:

One note: in the diagram, the one line on the right that didn't improve endurance was the guy that had gotten injured. He didn't get injured as part of the training sessions... but it does illustrate what happens when you cross the line and get hurt.